/**
 * Copyright 2014 National University of Ireland, Galway.
 *
 * This file is part of the SIREn project. Project and contact information:
 *
 *  https://github.com/rdelbru/SIREn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.sindice.siren.analysis.filter;

import java.io.IOException;

import org.apache.lucene.analysis.TokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;

/**
 * Filter that removes the trailing slash of the URI token.
 */
public class URITrailingSlashFilter extends TokenFilter {

  private final CharTermAttribute termAtt;

  public URITrailingSlashFilter(final TokenStream in) {
    super(in);
    termAtt = this.addAttribute(CharTermAttribute.class);
  }

  @Override
  public final boolean incrementToken() throws IOException {
    if (!input.incrementToken()) {
      return false;
    }

    final int bufferLength = termAtt.length();
    // Remove trailing slash
    if (termAtt.buffer()[bufferLength - 1] == '/') {
      // Strip last character off
      termAtt.setLength(bufferLength - 1);
    }
    return true;
  }

}
